This is a request for funds to replace a Hitachi HU-11B transmission electron microscope that was purchased in 1966 for the Electron Microscope Laboratory of the Zoology Department of the University of North Carolina. The EM Laboratory also contains a Zeiss 9S microscope, equally old, the performance of which is sufficient only for low resolution imaging and teaching. Neither of these outdated instruments meets the research needs of our NIH user group. Our requirements for a modern electron microscope include: eucentric goniometer stage for tilting and rotating the specimen; a low-dose exposure system to prevent damage to the specimen by the electron beam while focusing; parfocal lenses over the magnification range, 100-300,000X; accurate photographic exposure control and numerical identification of photographic negatives; uniform illumination; full-field view at low magnification (100X), and high resolution at high magnification (300,000X); the capability to add SEM and STEM modes of operation in the future. The Department of Biology, has been selected by the University for program expansion in the areas of molecular, cellular and developmental biology--four new tenure-track faculty positions are to be filled in the next four years. A modern electron microscope is essential to support and enhance this program expansion, as well as to meet the research needs of the current NIH-supported investigators.